1. Field of the Invention
The present invention relates to pressure sensors and devices for measuring pressure, and, more particularly, to a pressure sensor and a device for measuring pressure using this pressure sensor capable of flexibly supporting the shape or size of a mounting target or a pressure detection target and also capable of accurately detecting surface pressure of a pressure detection target.
2. Description of the Related Art
Conventionally, pressure sensors that detect pressure by converting applied pressure to an electrical signal have been known. Some of such pressure sensors detect pressure by using an elastic member such as a rubber as a component therein, utilizing the deformation of the elastic member by pressure.
For example, Patent Document 1 (Japanese Patent Application Laid-Open Publication No. 10-318865) discloses a pressure sensor in which an elastic member containing metal powders admixed therein and an exciting coil are disposed adjacently to each other. Being in a state that a voltage is applied to the exciting coil, the pressure sensor detects pressure as a loss of an eddy-current which occurs upon application of a load to the elastic member.
Also, Patent Document 2 (Japanese Patent Application Laid-Open Publication No. 2000-346606) discloses a pressure sensor in which an elastic member is provided between a permanent magnet and a hall element. This pressure sensor detects applied pressure based on a change in eddy current which occurs upon application of a load to the elastic member.
However, the technology disclosed in Patent Document 1 has a problem in which pressure detection accuracy depends to a large degree on the quality of the elastic member containing the metal powders. That is, upon preparing the pressure sensor, distribution density of the metal powders to be mixed into the elastic member is required to be accurately controlled. Therefore there is a problem of low yields of sufficiently accurate pressure sensors.
The technology disclosed in Patent Document 2 has a problem in limitation of size reduction of the permanent magnet. Therefore this sensor can not be adapted to small pressure detection targets. For this reason, this pressure sensor is not suitable for the purpose of measuring surface pressure with discrete pressure sensors being arranged in an array. Furthermore, there is also a limitation in increasing size of the hall element, and therefore this sensor cannot be adapted to large pressure detection targets.
From those mentioned above, there is a major demand in realizing a pressure sensor that is applicable to a variety of pressure detection targets, capable of accurately measuring pressure, capable of being readily arranged in an array, and capable of efficiently measuring surface pressure.